Method of converting metal compounds.



ummfiz l. PAT-EDITED D30.- 15, 1903.

' J. W.'MAODOHALD.

METHOD OF GONVERTING METAL camouuns.

AYPLIOATIOH FILED MAB-. 26. 1903;

.HO MODEL.

Wane/bow m: annals PETERS m mamumo" WASHINGTON m c UNITED STATES Patented December 15, 1903.

PATENT OFFICE.

JOHN W. MAODONALD,OF PITTSBURG, PENNSYLVANIA, ASSIGNOR T 0 UNITED STATES SULPHIDE SMELTING FURNACE COMPANY OF TOLEDO, OHIO.

METHOD OF CONVERTING METAL COMPOUNDS.

SPECIFICATION forming part of Letters Patent No. 746,721, dated December 15, 1903.

Application filed March 26, 1903.

To all whom it may concern.-

Be it known that I, JOHN W. MACDONALD, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented new and useful Improvements in Methods of Converting Metal Compounds; and I do-hereby declare the following to be a full, clear, and exact description of said invention, reference being had to the accompanying drawings, and to the figures of reference marked thereon, which form a part of this specification.

My invention relates particularly to that branch of the art in which the compounds of iron, sulfur, copper, gold, and silver in the form commonly known as matte are converted to metal by the well-known process of injecting a strong current of air into the body of such compounds while in a molten state; audit consists of animproved method of introducing a fluxing material into such molten compounds, substantially as herein described and claimed.

That those skilled in the artlto which this improvement appertains may put the same into operation the following specification, taken in connection with the accompanying drawings, forms a full, clear, and exact description thereof.

In converting these heavy compounds to metal by the process referred to itis necessary to add a quantity of fiuxing material thereto as the operation proceeds, which material is generally rock silica, and the apparatus usually employed in working under said process consists of a metal shell-like converter of such form and construction as will permitof itsv being moved from place to place about a converting plant with mechanism specially designed for the purpose. The many unsuccessfu 1 attempts heretofore made to introduce this silica while in a molten state and in other forms into these compounds demonstrated that it isa requirement of the process that the silica must reach and be kept within the area of rapid oxidation going on in the converter during the operation. The method now generally followed to meet this requirement is to mix the silica with some plastic material and tamp it into the converter to serve as well for a lining for the shell as to supply the silica necessary to .the operation Serial No. 149,743. (No model.)

to be carried on; but as the operation proceeds this lining is rapidly dissolved, and in order to replace the same the shell must be Withdrawn from commission, resulting in delays, which may be short or long, according as the number of shells available be many or few, and for but an ordinarily well-equipped plant such a number of these shells must be provided,'together with proper apparatus for handling them, that the cost of installing a modern converter plant is very large.

This improved method renders unnecessary the large outlay required in installing a plant to carry on the method now in use and very greatly red uces the costof operation by avoiding delays and by large saving in the labor cost resulting from the necessity of relining the shells.

This method may be adopted in operating with a converter apart from a smelting-fur- ;nace,"or, if desired, it may be used in connection with and form a part of such furnace.

The accompanying drawings illustrate the operation of this method when operating with a converter apart from a smelting-furnace.

In the drawings, Figure l is a vertical section of the converter. Fig. 2 is a plan view of the same.

The converter is formed with a cast-iron casing lined with brick made of material knownrto resist the corrosive action of the compounds to be operated upon and has a roof 1, consisting of sheet metal arranged to form a water-jacket, and may be of any suitable length, according as the work demands. Attached to the roof are several open-ended tubes 2, the lower ends of which extend down into the body of the converter and are provided with metal casings to form a waterjaoket 3 ,which, together with the jacket forming the roof, are supplied with water by proper connections. The upper parts of saidtubes project upward from the roof and are provided with means for closing the ends thereof, such as a cover or lid 20. In the hearth of the converter a depression 4 is formed, wherein the metal settles as it is blown down from the body of the compounds operated upon, from which point it may be drawn 0% through a tap-hole provided for that purpose. The converter is charged through the opening 5, which is closed by a slide. As the slag is blown up it may be drawn off through a tap-hole near the upper part of the hearth. A series of openings 6 in one of the side walls admits the blast and directs it down into the body of the compounds upon the converterhearth.

To put this method into operation, pulverized silica mixed with a small quantity of plastic clay is formed into cylindrical or other preferred form and baked to hardness. When the body of the converter has been well freed of moisture, one of said cylinders of silica 7, still hot from baking and thus free of moisture, is placed in each of the tubes extending down into the converter and allowed to drop down therein until the lower end thereof rests upon the hearth of the converter. The molten-metal compounds may uowbe charged into the converter until they form a body reaching up to and just surrounding the base of the water-jacketed tubes holding the cylinders of silica, during which time the blast may be turned on. It will be seen that as the cylinders of silica are held in upright position by their inclosing tubes and are of such length that they will have sufficient Weight to overcome the difierence in the specific gravity of the two bodies the lower ends thereof will always rest upon the hearth of the converter, though the heavy compounds rise up and around about them, and being thus held in position by said tubes the silica cylinders must remain down in the body of the compounds while the operation of blowing the same to metal proceeds. The lower ends of these cylinders will thus be brought into the immediate field of rapid oxidation going on during the blow, and as they cannot escape therefrom they will always be open to attack, and therefore must furnish the silica known to be required in carrying on the operation and which in the methods now in general practice is drawn from the lining of the converter. As the blow proceeds and the exposed portion of each cylinder is dissolved, and thus undermined, the cylinder will drop down in its tube, and thus nearly always offer the same area of surface to attack, and as the cylinders waste away they can be replaced by others without interruption to the blow by passing them into the tubes through the openings in the upper ends thereof.

To one familiar with the process and methods now in general use it will be seen that there is not necessarily any reason why operations conducted under the method here described cannot be made continuous. The compounds can be charged into the converter without shutting off the blast, the slag blown up can be drawn off while the blowing goes on, and it is plain that the metal settling in the depression in the hearth can be drawn off from time to time as it accumulates without interruption to the blow.

The amount of silica required for a given output of metal is such that it will permit of making the cylinders here shown of such size that no inconvenience will be experienced in their handling nor in arranging the mechanics of the special form of converter required to operate under this method.

It will now be understood that in carrying out my invention I first press the fiuxing material into an elongated solid body and then hold it within the bodyof molten compounds in the converter while said compounds are being converted to metal. Owing to the support for the body of the fluxing material, the latter will automatically feed into the body of molten'compounds, which feed will be antomatically limited in rate to the rate of dissolution or undermining of the body, gravity serving to preserve the continuity of the au-.

tomatic feed.

Having now described my invention, I claim 1. A method of extracting metals from molten compounds thereof, which consists in holding an elongated solid body of fiuxing material with its lower end within a body of such compounds while converting the same to metal, as set forth and described.

2. A method of extracting metals from molten compounds thereof, which consists in holding an elongated solid body of fiuxing material with its lower end within the area of highest oxidation the body of such compounds, and keeping said fiuxing material withinv said area of oxidation while converting said compounds to metal, as set forth and described. 7

3. A method of extracting metals from molten compounds thereof, which consistsin introducing into a body of molten compounds a solid body of fluxing material of such form and dimensions as that a portion thereof will sink into said molten compounds, and into the area of highest oxidation during the operation of converting said compounds to metal, and be held therein, as described and for the purpose set forth.

4. As an improvement in the art of smelting ores, the method of continuously supplying a fluxing material to a converter, which consists in automatically feeding a solid body of such material into the body of molten compounds in the converter, and holding it therein, and automatically limiting the rate of feed to the rate of dissolution of such material.

5. As an improvement in the art of smelting ores, the method of continuously supplying a fluxing material to a converter, which consists in holding a body of such material against the bottom or hearth of the converter and feeding said body by gravity as its lower portion is undermined.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN W. MACDONALD.

Witnesses:

H. JOSEPH DOYLE, FRANK D. BLAcKIsToNE.

IIO 

